1. Field of the Invention
The present invention relates to a cyclone separator for removing a fine substance such as a fine powder produced as waste during a machining process.
2. Description of the Related Art
Machining processes are carried out by feeding a cutting liquid from a feed tank in a machining apparatus, and the used cutting liquid contains a fine powder as machining waste. The cutting liquid containing the fine powder as the machining waste is supplied to a filter device, and the cutting liquid devoid of the machining waste after filtering is recycled to the feed tank (for example, Japanese Unexamined Patent Application Publication No. 2001-137743).
While the machining waste is removed, for example, with a filter membrane of the filter device, or the machining waste is removed by precipitation, there is a problem in that a large amount of the machining waste contained in the cutting liquid cannot be reliably removed within a short period of time using a small device. The filter membrane may become clogged, and the clogged filter membrane needs to be cleaned after disassembling the filter device. The filter membrane needs to be exchanged when it is disabled even after cleaning. Since the filtration accuracy deteriorates and the filter membrane becomes readily clogged by repeated use, most of the filter membranes are in the form of disposable membranes. Accordingly, the filter cost becomes expensive.
The problem of clogging may be solved by using a cyclone separator in place of such a filter device, since the liquid containing the fine substance is introduced from a liquid flow-in passageway to generate an eddy flow at a given flow rate, the fine substance is transferred toward an outer circumferential side by applying a centrifugal force to discharge a fluid after separating the fine substance, and the separated substance is precipitated by decelerating the eddy flow (for example, Japanese Unexamined Patent Application Publication No. 10-286493 and 2000-288425).
Since the cyclone separator has one liquid flow-in passageway, the liquid flow-in passageway should be narrowed to increase the flow rate of the eddy flow. However, the pressure loss increases by narrowing the liquid flow-in passageway making it difficult to obtain an appropriate flow rate during processing.
In addition, forming the eddy flow from one liquid flow-in passageway generates a turbulence in the eddy flow, and a satisfactory separation accuracy cannot be obtained since particles cannot be easily separated into particles having accurate particle diameters.
While a high processing flow rate may be obtained by providing a plurality of liquid flow-in passageways for feeding the liquid, the cyclone separator necessarily becomes larger as a result of the plural pipe lines, making it difficult to provide an installation area.